I've put together a new i3 Rework variant. I've had a couple of prototypes running for about a month. It can easily print 100 micron layers and I've used the machine at 60 microns. At 300 microns I've been printing at 100 mm/sec with a .4 nozzle easily.(I plan to test it at faster speeds with a larger nozzle) It's a mashup using the basic design of the Graber i3 frame (with some mods to the size and Y belt motion parts), a modified Wilson/i3 direct drive extruder, a Hephestos based X motor end and a X idler end that employs an adjustable belt tensioner. The assembly goal is to make the machine as easy to assemble as possible with as many "positive fit" parts and assemblies as possible. A positive fit means the part only assembles one way with minimal adjustment needed.
The design is meant to be as DIY friendly as possible allowing those with access to a maker space to build one entirely at the space. The Graber based frame can be either wood, melamine, ACP (Dibond) or metal. I've found laser cut melamine to offer the best bang for the buck. By eliminating the threaded rod frame the design is easier to align and square as it only goes together one way. It also provide more stability compared to a single plate i3 design or a threaded rod frame i3 Rework design. This is technically a Repstrap (as opposed to a Reprap) as such the printed parts count is reduced from about 10-12 hours of printing to about 5 hours. If the only access you have to a printer is at your makerspace you know what a pain it can be to log enough hours to print a set of parts. The design replaces 5-6 hours of printing with 30-40 minutes of laser cutting or CNC routing. The design eliminates the threaded rod frame and a considerable number of fasteners.
Source is at [
github.com] with the derivative works listed as well as editable source for the parts that are original to the machine.
Assembly docs are at [
roaddoglabs.com] . There is also a more detailed description of the machine and info on what was changed from the derivative parts. Build docs are still a work in progress.
A detailed BOM is still a work in progress though most fasteners are M3 x 14. A starting point for the BOM is at [
roaddoglabs.com]. As the build docs are completed the BOM and supporting docs will be updated. I'm still tweaking a few things and those are listed in the issue tracker at Github.
I'll get some more pics once I get the BOM finished and the build docs complete.
Disclosure: I'm Dave Stevens, my wife and I operate Roaddog Labs Ltd, a kit integrator/ digital fabrication shop in Las Vegas, NV. We've been selling kits and parts for the last few years. We will sell this as a full kit or as an upgrade for those with other frame designs that want something more stable but still maintain the geometry of an i3 Rework. That said, the source is available fully open, no restrictions.